Nearly a week has passed since the start of the Mists of Pandaria Beta. Pet Battles, collecting wild pets, account wide pets, pet renaming, and the ability to trade/sell BoP pets have not been fully implemented for testing yet.

However, we've found some awesome goodies during our initial run on the testing servers!

New Pets
The Darkmoon Rabbit is a new BoU pet of epic quality that was datamined the very first day of MoP beta. It's unknown how players will be able to obtain this companion, but there is an achievement (That Rabbit's Dynamite!) that requires players to "Slay the ferocious Darkmoon Rabbit". This achievement does not have any rewards attached to it at the moment, but we're not ruling it out as being tied to the pet in some way.

Other than the Darkmoon Rabbit, Wowhead found 5 more new potential companions hiding in the beta! So far these pets only have spell IDs. [source]

Beaver Yearling

Porcupette

Raccoon Kit

Tiny Water Strider

Otter Pup

Wild Battle Pets
Another new feature is the ability to track wild pets on the minimap! All critters flagged as "Wild Battle Pets" will show up as orange bunnies on the minimap (pictured above).

Many of the critters share similar models to existing companions, but there are a few new zone-specific ones such as the Tiny Bog Beast found in the Wetlands and the Tiny Harvester found in Westfall.

So far only the Eastern Kingdoms seem to have been populated with these critters, and we'll have to wait to see what types of pets Kalimdor will have to offer.

Along with being able to track them, a new cursor icon is displayed when hovering your mouse over the actual critter (video below). Rather than a sword icon, players will see a new crosshair. Players can still attack and kill these critters, however right and left clicking (with and without a companion pet out) while using the crosshair icon only yields an error message at the moment.

We assume that all of these Wild Battle Pets will be collectible after using companions to fight them. But we're not 100% sure since pet battling hasn't been implemented on the beta yet. We'll just have to wait and see!

Pet Classes and Battle Abilities
Pets will fall into one of 10 possible pet classes. Each pet class has its own strengths and weaknesses when up against certain other companion classes.

Mechanical (Mechanical attacks deal bonus damage to Humanoid companions and less damage to Mechanical and Water companions.)

Mythical (Mystical attacks deal bonus damage to Dragons and less damage to Animal and Mechanical companions.)

Water (Water attacks deal bonus damage to Mechanical and Dragon companions and less damage to Water and Humanoid companions.)

Elemental (no info yet)

Humanoid (no info yet)

Undead (no info yet)

Although Pet Battles aren't ready for testing yet, Wowhead has organized a list of possible spells and abilities for each class of battle-ready companions.

Pet Battles Achievements Tab

Lastly, there is a new Pet Battles tab in the achievement window, but it currently does not have any specific achievements listed. We expect this tab will be populated with interesting and fun Pet Battle goals in a future beta build.

More to Come...
It's still very early in the testing phase and much of the new Pet Battle content is unavailable, so many things could change. We'll be keeping a close eye on the wild pets as well as the other anticipated features. Be sure to check back for more beta updates!